Explore Eco Regions

This is the most severely altered of Texas' ecoregions, since most of the historic Blackland Prairie has been converted for cropland or urban development. Less than one percent of the Blackland Prairie remains in an uncultivated state. This amounts to only an estimated 5,000 acres remaining in its historic condition in terms of plant species. Also, only a small percentage of public and non-profit conservation land and private properties are operated under wildlife management plans.

All habitats in this ecoregion are threatened by rapid population growth and accompanying conversion to urban areas and pastureland, fragmentation and decreased land parcel size. It ranks lowest in number of rare plant species and seventh in number of endemics, but all four native Blackland Prairie grass communities are rare.

The region is an important stopover habitat for migrant songbirds and wintering raptors, but many tall grass prairie birds have declined drastically due to land conversion and fragmentation. Priority actions include protection and restoration of remnant prairies.

Central Great Plains (Rolling Plains)

The ecoregion has a relatively small amount of public and non-profit conservation land and a medium percentage of land under wildlife management plans. Threats include land fragmentation and conversion. Also, exotic species such as salt cedar exist along many miles of riverbank. The only rare plant endemic to this region, the Texas poppymallow, is associated with the mesquite grasslands and Havard shin oak communities.

Regarding rare animals, low forests on limestone out-pockets are important habitat for the endangered Black-capped Vireo. Both the federally listed Concho and Brazos water snakes occur here. The state listed Texas kangaroo rat also survives in this region. This region is a prime candidate for restoration efforts and many species would benefit from restoration of grasslands and riparian forests.

Protection of the Texas poppy-mallow and high quality examples of communities such as Havard oak-tallgrass, sandsage-midgrass and cottonwood-tallgrass grasslands and woodlands are also important.

Chihuahuan Deserts (Trans-Pecos)

This is the most conserved of all ecoregions, but conserved lands are not evenly distributed. The desert grasslands of the region are poorly conserved, as are much of the forests along the Rio Grande and plant communities around springs. Threats are the lowest of any ecoregion but include persistent drought and groundwater withdrawals that have damaged many existing spring-associated communities. Expansion of human activities in the El Paso region will negatively impact habitats in the surrounding areas.

Botanically, the region is one of Texas’ richest and most unique. Approximately one of every 12 plant species occur nowhere else in Texas. The Chihuahuan Desert supports three times the number of rare plants than any other region. Much of the banks of the Rio Grande are choked with salt cedar, making the protection of the rare patches of cottonwood-willow and velvet ash-willow communities important. Many springs and their associated ciénegas and creeks once contained numerous rare plants, but most have dried out.

Of the few springs that remain, only three are permanently conserved. Where animals are concerned, this region has the highest percentage of vertebrate species of concern. The bird, mammal and insect faunas are rich and unique. Rare birds include the Golden Eagle, Common Black Hawk, Elf and Flammulated Owls, Peregrine Falcon, Montezuma Quail and others.

Mammals include the black-tailed prairie dog, kit fox, desert bighorn, pronghorn, Mexican black bear and hooded skunk. This is by far the most herpetologically diverse ecoregion. Species of concern include the Chihuahuan mud turtle and the dunes sagebrush lizard. Additional conservation actions are needed to protect the high desert grasslands, spring communities and riparian woodlands along the Rio Grande.

Cross Timbers (Cross Timbers and Prairies)

This ecoregion has little public land, few private preserves and a low percentage of private land under wildlife management plans. Threats include fragmentation and land conversion of prairies, forests and savannahs, mesquite invasion of degraded grasslands and proliferation of exotic grasses.

Rivers and streams have been altered by an extensive reservoir system. Hundreds of miles of riparian, or river, forests have been inundated and downstream flows reduced. Most ground nesting birds, grassland mammals, amphibians and egg-laying reptiles are also threatened by fire ant invasion. This ecoregion harbors only one rare plant and has relatively low endemism.

Patches of Blackland Prairie grasslands within the Cross Timbers are made up of threatened communities similar to those described for that ecoregion. Regarding rare animals, the region provides nesting habitat for the federally endangered black-capped vireo and the golden-cheeked warbler. Priority actions include protecting the ecoregion’s prairies, woodlands and remaining river corridors.

East Central Texas Plains (Pineywoods)

This region has only a small percentage or public or non-profit conservation land. Primary threats are fragmentation and land conversion, especially from the damming of springs, streams and rivers. Other threats include fire ant infestation and fire suppression in both oak savannahs and pitcher plant bogs.

Plant endemism in this ecoregion ranks lower than others, though the area supports 17 rare species and 65 endemics. Many highly specialized plant habitats such as blowout sandhills, clay-pan savannahs, pitcher plant bogs, Catahoula and Oakville sandstone outcrops, chalk glades and limestone prairies support numerous rare plants which are not found on public land.

Regarding rare animals, Example Species include the Loggerhead Shrike, Painted Bunting, Spotted Skunk and Brazos Water Snake. Conservation efforts in this region should focus on areas that support many unique species and communities such as mesic hardwood woodlands, bogs, sandhills and bottomland hardwoods.

Edwards Plateau

Despite a small amount of public and non-profit conservation land, the region has a relatively high percentage of private land managed under wildlife management plans. Projected population growth and subdivisions of large tracts of land are high, particularly in the eastern portion where intense development and fragmentation threatens the biodiversity and the region’s unique hydrology.

Regarding plants, the Edwards Plateau is internationally recognized for its unique flora and its karst (cave) systems. It has the highest plant endemism of any ecoregion in the state and ranks third in number of rare plants. Of the 29 plant communities found here, three occur nowhere else in Texas and two are found nowhere else in the world. In terms of rare animals, karst habitats support many species of salamanders and cave insects, many of which are restricted to only a few sites.

This is the state’s most important ecoregion for herpetological and invertebrate species due to high endemism, sensitive habitats and intense threats. The endangered Black-capped Vireo and Golden-cheeked Warbler are the two bird species of greatest concern. Public and private conservation priorities include protecting the sheltered canyons, springs, caves and river systems that are home to most of the biological diversity.

Another priority is conserving relatively intact grasslands and maintaining sufficient old growth juniper habitat for the Golden-cheeked Warbler, especially in the western Hill Country.

Gulf Coast Prairies and Marshes

Overall, this ecoregion ranked relatively high in conserved status second only to the Chihuahuan Desert ecoregion, although conservation efforts are not evenly distributed across the region. Coastal marshes and barrier islands are relatively well conserved, whereas inland prairies, coastal woodlands and some beach habitats are not.

Increased population growth and associated development along the coast have fragmented land, converted prairies, changed river flows, decreased water quality and increased sediment loads and pollutants within marsh and estuarine systems. The region ranked high in rare plant species and endemism including five rare plant communities. All of the region’s 24 rare plants occur inland where the conserved status is lowest.

Rare animals include the Attwater’s Prairie Chicken, Whooping Crane, Aplomado Falcon, White-tailed Hawk, Gulf Coast Hog-nosed and Eastern Spotted Skunks, all of which need attention, as do many bird species that depend on this important migratory stopover area. Protection efforts should focus on inland prairies and coastal woodlands, although many beach areas and mud flats need additional protection.

High Plains

This ecoregion is the least conserved, with a low percentage of public and non-profit conserved land and land under wildlife management plans. It has experienced a high rate of conversion to crops, but a considerable portion of it is now enrolled in the USDA’s Conservation Reserve Program, affording higher conservation value than cropland.

Threats include fragmentation and land management practices that are harmful to species such as lesser prairie chickens. Other threats include the damming of springs, streams and rivers, the draining and conversion of playa lakes and surface mining. Plant endemism is low, but there are two rare species, five endemics and several distinct plant communities.

Birds of concern in this region include the Ferruginous and Swainson’s Hawks, Burrowing Owl, Mountain Plover and High Plains Lesser Prairie Chicken. The black-tailed prairie dog, swift fox and pronghorn need conservation attention as well. Priority actions include increasing the percentage of conserved land to support several important game species and threatened animals.

South Texas Plains

This ecoregion consists mostly of level to rolling terrain characterized by dense brush. Little of the brush country is conserved on public lands, but a relatively high percentage is in large stable ownerships and operated under wildlife management plans.

Much of the high quality brush habitat that still exists in the Lower Rio Grande Valley is in public ownership, but it is insufficient to sustain many of the region’s threatened plants, animals and communities. Threats are concentrated in the valley due to the expanding human population, fragmentation, conversion to croplands, urban development, insufficient river flow and introduction of exotic plants.

Rare plant communities include the Texas ebony-anacua, Texas palmetto and Texas ebony-snake-eyes assemblages. Rare species include Walker’s manioc, star cactus, Texas ayenia and Zapata bladderpod. In terms of animals, the valley has particularly rich bird and butterfly faunas as well as the endangered ocelot and jaguarundi.

The remaining fragments of brush in the valley should be protected and corridors between these habitats should be protected and restored.

Southwestern Tablelands (Post Oak Savannah)

Here are elevated tablelands with red-hued canyons, mesas, badlands, gorges, and dissected river breaks in a topography that is mostly broad, rolling plains. Because of the rough terrain, most of the land is in arid livestock production, and may include hunting as a primary use. Very little urban development occurs in this ecoregion as the rough terrain deterred much settlement.

Oil and gas production are also evident in land use. The rivers and their tributaries within this ecoregion are inhabited by some of the rare and unique fauna of Texas such as the Concho Water Snake and the Brazos Water Snake. Sand bars on the upper reaches of these rivers provide nesting habitat for the Interior Least Tern and the Snowy Plover.

The Palo Duro mouse, a close relative of the Pinyon mouse of the Rocky Mountains, can be found in the juniper woodlands on the steep canyon breaks; Texas kangaroo rats burrow at the base of mesquite trees on certain clay loam soils of these Rolling Plains.